RAB11B Protein, Human (HEK293, His)

The small GTPase RAB11B, a member of the Rab family, plays a pivotal role in intracellular membrane trafficking, orchestrating processes ranging from the formation of transport vesicles to their fusion with membranes. This GTPase undergoes a cycle between an inactive GDP-bound form and an active GTP-bound form, recruiting distinct downstream effectors that directly govern vesicle activities, such as formation, movement, tethering, and fusion. Specifically, RAB11B is implicated in endocytic recycling, where it regulates the apical recycling of transmembrane proteins, including cystic fibrosis transmembrane conductance regulator (CFTR), epithelial sodium channel (ENaC), potassium voltage-gated channels, and voltage-dependent L-type calcium channels. Furthermore, it participates in the control of constitutive and regulated secretion, such as insulin granule exocytosis. RAB11B is essential for melanosome transport and release from melanocytes and is involved in regulating V-ATPase intracellular transport in response to extracellular acidosis. Additionally, it promotes Rabin8/RAB3IP preciliary vesicular trafficking to the mother centriole, forming a ciliary targeting complex that includes Rab11, ASAP1, Rabin8/RAB3IP, RAB11FIP3, and ARF4, thereby regulating the initiation of ciliogenesis. Conversely, under LPAR1 receptor signaling pathway activation, interaction with phosphorylated WDR44 inhibits Rab11-RAB3IP-RAB11FIP3 complex formation and suppresses cilia growth.